Machines, such as excavators and power shovels, may include a deck or other platform that rotates above continuous tracks, wheels, pontoons, etc. Extending from the deck, the machine may further include a boom for an articulated arm or crane designed to operate a bucket, a breaker, a hook, or any other such work tool. Accordingly, such machines typically include one or more actuators designed to move the tracks, rotate the deck, and operate the articulated arm and work tool.
By way of example, an excavator or power shovel may typically operate in work cycles which may include digging, lifting, swinging, dumping, and returning steps for operating a bucket to dig and load fragmented rock, earth, minerals, overburden, and the like for mining or construction purposes. The operation of rotating the deck of the machine is generally powered by a motor or other such means. Most of the time the motor or such means are designed oversized to make the machine capable of operating under heavy loads. Other requirements may include making an existing or older machine handle operations like dredging, or any other such operation requiring to rotate the deck under heavy load on the bucket. Thus, the machine operates with a motor that is oversized for majority of its power demand profile. The oversized motor affects initial purchasing cost, operating and repairing costs, and any probability of retrofitting the existing or older machines to handle dredging operations.
G.B. Patent No. 8,198,64A (hereinafter referred to as '864 reference) describes a slewing motor for jibbed machines like cranes, excavators, etc. The '864 reference includes a pinion secured to a slewing part of the machine and a circular rack secured to a stationary part. The motion is provided by controlling valves providing operating fluid. However, the '864 reference does not disclose details about any solution for reduction in motor size or retrofitting older machines for dredging like operations.
Therefore, an improved slewing system for the machine is required.